But what is it? According to Outdoor Magazine, it's probably something called a sea lamprey, a type of parasite regularly found in the northern Atlantic region. The lamprey uses its terrifying, alien-like teeth to latch onto its prey before injecting it with digestive fluids that eat away at and kill the fish (or, innocent swimmer). Only one out of seven fish/humans survive the attack. Lampreys are apparently becoming increasingly common in fresh water areas, like the Great Lakes and rivers in New Jersey.

Of course, experts aren't entirely certain it's a sea lamprey and not something more obscure or horrifying. "The photo doesn't allow counting of gill openings (seven per side for sea lampreys), but based on size alone, this does appear to be a sea lamprey," a New York Department of Environmental Conservation spokeswoman told Outside Magazine, according to the New York Daily News. As BuzzFeed notes, that's almost a certain sign that it's an actual monster, and not your run-of-the-mill monstrous river parasite.

Regardless of what it is, this is just another reason why you should never swim or wade in murky water, even/especially in New Jersey.